The overall objective of better defining the functional characteristics of the normal and diseased left ventricle in man will be accomplished through the further development and application of new techniques for evaluating global and regional left ventricular performance during various types of physiologic and pharmacologic stress. The more specific tests are as follows: (1) Techniques for determining left ventricular chamber dimensions and volume in subjects at rest and during stress using epicardial markers which are attached at the time of surgery will be further evaluated and applied to assess ventricular performance. (2) Techniques which have the potential for more accurately determining left ventricular dimensions and volume and changes in these parameters by echocardiography will be evaluated and applied. (3) Methods for determining regional left ventricular chamber border motion from biplane cineagiograms in terms of extent, time and velocity will be further evaluated and applied to evaluate regional left ventricular performance at rest and during stress in man with and without heart disease. (4) By using above techniques the relationship of ventricular performance determined at rest and during exercise and pharmacologic stress will be determined. (5) A new technique for quantifying the extent of coronary artery narrowing from coronary arteriograms will be further evaluated and applied to determine the relationship between extent of coronary narrowing, symptoms of angina pectoris, segmental myocardial performance and segmental myocardial perfurion.